The present invention relates to a method of applying heat to food for preparing food without using fire at indoors, particularly at resorts and the like, and a utensil directly used for carrying out the method.
Cooking methods are roughly classified as boiling, steaming, sauteing, frying, casseroling, and baking or roasting.
Heating methods are divided into a traditional heating method using combustion gas and a modern fireless heating method by high-frequency heating or eddy-current heating.
Water, oil and air are used as a thermal medium in a heating utensil.
Cooking utensils of glass or earthenware for boiling, steaming, sauteing, frying, casseroling, baking or roasting can be heated by burning gas, but cannot be heated by eddy-currents. These materials also have the drawback that they break easily when exposed to excessive heat or when subject to a physical external force, such as dropping or shock.
Metallic materials available are aluminum, copper, stainless steel, and iron. The first three materials have the drawback that they cannot be applied to utensils for cooking by eddy-current heating. Enameling has the drawback of the surface material separating when heated without water.
Heating by gas has the advantage of quick heating and low cost, but has disadvantages, such as scorching caused by failure to turn off fire and danger of gas poisoning or explosion caused by extinction during cooking with a slow fire or by gas which leaks from the equipment in use.
Eddy-current heating has the following disadvantages: slow heating, high cost of an eddy-current generating unit, and high cost of energy due to the use of electricity. This heating method, however, has the following advantages: ability to heat with weak electric power, heating at a fixed temperature, and no danger of gas poisoning or explosion as a result of fire not being used.